A student uses a vertical forcemeter and a set of different loads to determine the weight of a uniform metre rule, as shown in the experimental setup where one end of the rule rests on a bench acting as a pivot, and the other end is supported by the forcemeter.
The student places a cylindrical load onto the metre rule. To locate the centre of the load, the student records the positions of its edges on the rule:
Determine the scale reading on the metre rule at which the centre of the load is located. Show your working.
The student measures the force FFF indicated by the forcemeter for different values of the load LLL. After plotting a graph of FFF on the yyy-axis against LLL on the xxx-axis, they find the line of best fit has the equation:
F=0.65L+0.84 F = 0.65 L + 0.84 F=0.65L+0.84State the value of the vertical intercept y0y_0y0 of the line on the FFF-axis.
The weight WWW of the metre rule is related to this intercept by the relationship:
W=2y0 W = 2 y_0 W=2y0Calculate the weight WWW of the metre rule.
Suggest one possible practical source of inaccuracy in this experiment, assuming the procedure is carried out carefully.
245 exam-style questions on CIE IGCSE Physics 1.5 Forces, covering 1.5.1a Forces, resultant force and motion, 1.5.1b Load–extension graphs and the spring constant, 1.5.1c Friction and drag, 1.5.1d Force, mass and acceleration, 1.5.1e Motion in a circular path, 1.5.2a Moment of a force, 1.5.2b Principle of moments and equilibrium, and 1.5.3 Centre of gravity and stability. Each one has a worked solution and a mark scheme showing where the marks go.